Apparatus for making spiral tubing.



E. T. GRBBNFIELD. APPARATUS FOR MAKING SPIRAL TUBING.

APPLICATION FILED APR.Z9,1908.

Patented Nov. 9, 1909.

EDWIN '1. GREENFIELEOF KIAMESHA, NEW YORK.

APPARATUS FOR MAKING SPIRAL TUBING.

Specification of Letters Patent.

' Patented Nov. 9, 1909.

' Application filed April 29, 1908. Serial No. 429,846.

To all whom it may concern:

Be it known that I, VEVDWIN' T. GREEN r'mnn, a citizen of the UnitedStates, residing at Kiamesha, in the county of Sullivan and State of NewYork, have invented certain new and useful Improvements in Apparatus forMaking Spiral Tubing, of which the following is a specification.

This invention relates to the manufacture of metallic tubing by windingor bending a strip spirally so as to form a series of successive spiralseach interlocked with and movable relatively to the spirals adjacentthereto.

The invention is of particular utility in machines of the type disclosedin Letters Patent Number 630,502 granted to me August 8, 1899.

In machines for making such spiral tubing, it is usual to employ one ormore pairs of die-rollers between which the strip or strips are passedto give the strip the desired transverse curvature, and eithera bendingdie or forming rolls for effecting the spiraling of the strips. Beforebeing spiraled, and if desired before being transversely curved, thestrip is carried into a bath of a galvanizing compound so that thecompleted tube is properly protected against rust. I

have found'that in bending the strip both to form it spirally and tocurve it transversely,

the galvanizing coating is cracked at nu- V merous points over thesurface of the strip and particularly on the edges thereof and burs ofthe coating are raised upon the surface of the'strip. These burs orflakes on the strip prevent forming the strip spirally as tightly as isdesired since they hold coacting surfaces of adjacent convolutions apartslightly.

My invention involves the provision of means for removing these flakesor burs, preferably during the spiraling operation, and for this purposeI prefer to employ a current of water for washing the flakes away. In amachine employing a bending die as disclosed in the atent abovedescribed, the die is provided with ducts through which a continuousstream of water is passed, these ducts being arranged in the mannerwhich will make the stream of the fluid most efi'ective in removing theflakes.

An apparatus embodying my invention is illustrated in the accompanyingdrawing in which- Figure 1 is a top view of the principal elements of amachine for making spiral tubing, Fig. 2 is an end view of the die, Fig.is a transverse section of the -d1e on line 3-3 of Fig. 4, Fig. 4 isa'section of the die on line ll' of Fig. 3, and Fig. 5 is a top view ofthe lower portion of the die.

Referring to these drawings, 1 indicates a die-roller mounted on a shaft2 and directly under these are a similar die-roller and shaft, the twoshafts being geared together at 3 and driven from a power-shaft 4 by agear 5. The two die-rollers have their peripheries shaped in the mannerwhich will give to a strip passed between them the desired transversecurvature, the strip 6 being arranged to pass through a groove in aguide 7 suitably mounted on the frame of the machine. The strip 6, inaddition to being laterally curved by the dierollers, is forced forwardthereby into the bending die by which it is spirally formed. The dieconsists of two semi-circular parts 8 and 9 each of which is secured toa semiannular casing 10, the two casings having dowel-pins and holes 11for positioning them relatively. The die and the casing therefor aremounted within a circular opening in a two-part holder 12 which isbolted upon the frame of the machine. In the two parts 8 and 9 of thedie is a central opening the walls of which have a spiral groove formedtherein corresponding in shape to the lateral, curvature given the strip6'by the die-rollers as shown in Fig. 4, andan opening 13 isprovidedthrough holder 12, casing 10 and the die through which the stripis passed to the central opening in the die.

Each part of the casing 10 is cut away on its inner face to form achamber 14 between it and the 'part of the die 8 or 9 adjacent theretoand an opening 15 is provided through the casing 10 with which a tube 16is connected, this opening leading to the chamber 14. In each of theparts .8 and 9 of the die are a plurality of radially-disposed ducts 17opening at one end into the chamber 14:. In the operative face of thebending die are a plurality of grooves 18 extending in a directionparallel to the axis of the die, (Fig. 4) with each of which one of theducts 17 communicates.

In the operation of the machine, a strip 6 is inserted through-thegroove in guide 7 and passed between the die-rollers 1. These rollerscurve the strip laterally and force it forward into the bending die bywhich it is formed spirally in a manner well understood. The strip isgalvanized before being introduced into the bendin die, if desired in aseparate and preliminary operation. While the strip is being spiraled,water is forced into the pipes 16 and chambers 14 and passes from thosechambers through the ducts 17 to the grooves 18. VVithinthe die thewater swirls around the strip as the latter is being bent by the groovedWalls of the die and washes away the flakes of the galvanizing compoundraised on the surface of the strip as the latter is bent by thedierollers and the bending die. The water forced into the die thusescapesat the ends of. the die through the grooves 18 carrying theflakes with it and may be caught in a suitable receptacle arranged.below the die. By the provision of such a rapidly moving current ofwater about the strip of metal while the latter is being spirallyformed, a much tighter tube can be made as the removal of flakes andburs of the galvanizing coating allows coacting surfaces of adjacentconvolutions to be brought into close contact. In starting the operationof spiraling a strip, the end of the strip is bent up slightly with asuitable tool so that the strip will not catch inthe grooves 18 butafter this the spiraling is continued in the usual manner and thegrooves 18 ofier no obstruction.

Having described my invention, what I claim as new therein and desire tosecure by Letters Patent of the United States is:

1. A machine for making spiral tubing havin a pair of die-rollers forcurving a strip laterally, a bending die having a circular openintherein the wall of which is provided wit 1 spirally-formed grooves anda plurality of grooves extending lengthwise of said open ng and crossingsaid spiral grooves, a plurality of openings through the die leadingto-said lengthwise grooves, pipes communicating with said last-namedopenings, and an opening through said die leading to saidspirally-grooved wall through which a strip may be forced into contactwith said wall, substantially as set forth.

2. A machine for making spiral tubing having a pair of die-rollers forcurving a strip laterally, a. bending die having a circular openingtherein the Wall of which is provided with spirally-formed grooves and aplurality of grooves extending lengthwise of said opening and crossingsaid spiral grooves, a holder for said die formed to provide a chamberbetween it and the die, pipes leading to said chamber, openings leadingfrom said chamber to said lengthwise grooves, and an opening throughsaid die leading to said spirally-grooved wall through which a strlp maybe forced into gontact with said wall, substantially as set orth.

This specification signed and witnessed this 27th day of April, 1908.

EDWIN T. GREENFIELD.

Witnesses:

D. J. EDMONDS, I. BARTLETT.

